I Love the Seeds Family Worship music. It's simply Scripture put to music. My girls love it and are beginning to hide God's Word in their hearts from singing and dancing to these songs.
I also really like the children's books written by R.C. Sproul. It's deep theology and Biblical truths brought to a child's level. He's written quite a few books that you can find on Amazon. We only have this one. I think the others are geared to older kids.